An electric circuit breaker device that breaks an electric circuit of an automobile, home appliances, or the like has been used to prevent severe damage at the time of an abnormality in the electric circuit itself or an entire system including the electric circuit. The importance of an electric circuit breaker device has become larger particularly in an electric circuit of an electric vehicle.
A known electric circuit breaker device contains, in a housing, an igniter, a projectile (piston), a conductor, and the like. References include US-A 2005/0083164 (Patent Literature 1), US-A 2005/0083165 (Patent Literature 2), US-A 2012/0234162 (Patent Literature 3), JP-A 11-232979 (Patent Literature 4), JP-A 2014-49300 (Patent Literature 5), and JP-A 2016-85947 (Patent Literature 6).
In Patent Literatures 1 and 2, metal, ceramic, and polymer are cited as examples of the material of a housing, and it is stated that a specific polymer is preferred (pages 2 and 3 of Patent Literature 1, and Page 2 of Patent Literature 2).
In Patent Literature 4, a casing 13 is made of stainless steel (paragraph No. 0011).
In Patent Literature 5, a case 30 has an electric insulation property, and is formed of a high-strength material (e.g., resin material) (paragraph No. 0034).
When a polymer material (resin material) is used, as is understood from FIG. 1 of each of Patent Literatures 1, 2, and 5, the housing (casing) needs to be formed thick to give necessary strength. When the stainless steel casing 13 is used as in Patent Literature 4, the mass increases, and since the casing 13 needs to be disposed in combination with an insulating case 14, the structure and assembly are complicated. Moreover, Patent Literature 4 is provided with an arc extinguishing chamber 32 for extinguishing an arc that occurs when an energized electrically conductive body is cut (Claims).
In Patent Literature 6, a metal cylinder is used to reinforce a resin housing, so that an effect unachievable in Patent Literatures 1 to 5 can be achieved.